I honestly was expecting this to be the case if you only had the PS4 version. What about if you already own the PS5 version on PS Plus?
They never did. I actually decided to contact customer support just a few weeks ago to finally get them to remove the PS4 version Plus license I redeemed last year, just so I could get the PS5 version. They never even fixed the screen where you actually redeem the game too.
One is the PS4 version, the other is the PS5 one. If pick the wrong one, then I guess you have to contact support again lol. This is also buried by the way behind the PS5's awful triple dot menu design.